1. Field of the Invention
The invention relates to a stand-alone appliance for general consumer use, which includes a control circuit which having a first input for receiving a first supply current, a second input for receiving a specific control signal, and a first output for a controlled activation signal; a functional member which comprises a second input for receiving said activation signal; a digital programming device which comprises a non-volatile memory section which contains a control program for said functional member in first memory locations, and which also comprises a volatile memory section for variable data, a third input for receiving a second supply current directly from a distribution member, a fourth input for a specification signal for said functional member, and a second output for said specific control signal; and externally activatable means for forming said specification signal.
2. Description of the Prior Art
There is a strong rise in the numbers of such appliances in use already. An appliance is to be understood to mean herein a so-called "consumer product" which does not require special skills for use; the appliance can be subdivided into two parts as if it were: the functional member which performs the actual consumer function, and the control which determines how this consumer function is realized.
Examples of such appliances are:
textile washing machines with various washing programs (the selection is determined by selective adjustment and/or measuring signals from sensors of given parameters, for example, in dependence of the nature and the quantity of laundry);
dish washers and electrical/electronic ovens, for which similar situations apply;
television receivers with built-in generators for games, preselection devices for given stations, for adjustment facilities, and the like;
vacuum cleaners whose cleaning power is determined in dependence of one or more parameters measured;
irradiation devices ("sun lamps") for domestic use with an adjustable irradiation time.
The embodiment described hereinafter is the best embodiment considered by the inventor; this irradiation device has already been described in part in the previous Netherlands patent application No. 7812150 and the corresponding U.S. Pat. No. 4,303,67 in the name of the assignee of this application and which are hereby incorporated by reference.
A large sub-category is thus formed by domestic appliances. The term "stand-alone" is to be understood to mean herein that the appliance can operate independently without being subordinate to an external device. In other words, it does not operate like a peripheral apparatus which is subordinate to a central computer.
Devices of this kind can in principle be switched on in two ways. The first way is by means of an on/off or reset switch or the like, so that the program is started under standard conditions. This is also the way used for professional equipment, for example, a digital computer and its peripheral apparatus (terminals). The second way of putting into operation is by applying the operating voltage to the device by insertion (or a similar operation) of the contact member into a contact position (for example, a wall socket) of the power source. The latter will often be done particularly in the case of devices which can be readily transported, because they can be stored after use. Such appliances often do not include such a costly reset switch. The second way of putting into operation produces a very unpredictable, prolonged and jittery switch-on phenomena on the supply voltage. For correct execution of the program the programming device should start at a predetermined address. As will be described in detail hereinafter, a microprocessor of the types TMS 1000 is used as the programming device in the embodiment in accordance with the invention. The starting address can then be generated, subject to special conditions, that is to say if either the supply voltage reaches a sufficiently high level within 3 milliseconds and does not decrease again (this requirement is often not satisfied), or if a specific voltage pulse is generated on an appropriate initiating input. Similar requirements are applicable to other programming devices. Such a programming device generally comprises a memory section which contains the (fixed) program. There is also storage space for variable data, such as one or more addresses for the program memory, intermediate results, parameter signals and the like. These variable data are lost if the supply voltage is interrupted.
A special problem with many of the above domestic appliances is that they influence a physical parameter value, such as a motor speed or a temperature. If an arbitrary data of the memory with volatile content can occur, said influencing is liable to take place in an incorrect manner and/or at the incorrect instant (for example, the washing machine starts to run directly upon inserting the power plug, or the irradiation lamp is set to complete an impermissible irradiation time).